AD 99-25-05

This amendment adopts a new airworthiness directive (AD) that is applicable to Hartzell Propeller, Inc., Model HD-E6C-3( ) series propellers, installed on Fairchild Dornier 328-110 series and 328-120 series airplanes. This action supersedes telegraphic AD T99-06-51 that currently requires initial and repetitive inspections of the propeller hub for cracks or grease leaks, and replacement of the hub if any cracks are found. This amendment requires an initial and repetitive inspections of Hartzell propeller hub, part number (P/N) D-5108-1, for cracks or grease leaks, replacement of the hub if any cracks are found, and allows the installation of propeller hub, P/N D-5108-5, as a terminating action for the inspection requirements. This amendment is prompted by the addition of propeller hub P/N D-5108-5 as a terminating action for the inspection requirements and by the removal of the inspection requirements for Hartzell propeller hub, P/N D-5108-5. The actions specified by this AD are intended to prevent severe vibration due to cracks in the propeller hub that could result in propeller blade loss, loss of control, and possible damage to the airplane.

Final rule; request for comments.

99-25-05 Hartzell Propeller, Inc.: Amendment 39-11448; Docket 99-ANE-18-AD. Issued November 24, 1999. Applicability: Hartzell Propeller, Inc., Model HD-E6C-3( ) series propellers with propeller hub part number D-5108-1, installed on but not limited to Fairchild Dornier 328-110 and 328-120 series airplanes.

Note 1: This airworthiness directive (AD) applies to each propeller identified in the preceding applicability provision, regardless of whether it has been modified, altered, or repaired in the area subject to the requirements of this AD. For propellers that have been modified, altered, or repaired so that the performance of the requirements of this AD is affected, the owner/operator must request approval for an alternative method of compliance in accordance with paragraph (e) of this AD. The request should include an assessment of the effect of the modification, alteration, or repair on the unsafe condition addressed by this AD; and, if the unsafe condition has not been eliminated, the request should include specific proposed actions to address it.

Compliance: Required as indicated, unless accomplished previously.

To prevent propeller blade loss due to cracks in the propeller hub that could result in loss of control and possible damage to the airplane, accomplish the following:

Initial and Repetitive Inspection Requirements

(a) Perform initial and repetitive visual inspections of the Hartzell propeller hub part number (P/N) D-5108-1 for cracks and grease leaks in accordance with paragraph 3.A. of the Accomplishment Instructions of Hartzell Propeller, Inc. ASB No. HD-ASB-61-021 Revision 1, dated March 18, 1999, as follows:

(1) Within 12 hours time-in-service (TIS) after the effective date of this AD, perform an initial visual inspection.

(2) Thereafter, perform a daily visual inspection. However, for airplanes that are not operated on a daily basis, inspect affected propeller hubs every operational day.

Confirmation of Crack(b) If a crack is confirmed, before further flight, remove cracked hub from service and replace with a serviceable part in accordance with paragraph 3.B. of the Accomplishment Instructions of ASB No. HD-ASB-61-021, revision 1, dated March 18, 1999.

Terminating Action

(c) Replace propeller hub P/N D-5108-1 with propeller hub P/N D-5108-5 within 600 hours TIS or three months after the effective date of this AD, whichever occurs first.

(d) Installation of propeller hub, P/N D-5108-5, constitutes terminating action for the inspection requirements of this AD.

Alternative Methods of Compliance

(e) An alternative method of compliance or adjustment of the compliance time that provides an acceptable level of safety may be used if approved by the Manager, Chicago Aircraft Certification Office (ACO). Operators shall submit their requests through an appropriate FAA Principal Maintenance Inspector, who may add comments and then send it to the Manager, ACO. Note 2: Information concerning the existence of approved alternative methods of compliance with this airworthiness directive, if any, may be obtained from the Chicago ACO.

Special Flight Permits

(f) Special flight permits may be issued in accordance with sections 21.197 and 21.199 of the Federal Aviation Regulations (14 CFR 21.197 and 21.199) to operate the aircraft to a location where the requirements of this AD can be accomplished.

Incorporation by Reference

(g) The actions required by this AD shall be done in accordance with Hartzell Propeller, Inc. ASB No. HD-ASB-61-021, Revision 1, dated March 18, 1999. This incorporation by reference was approved by the Director of the Federal Register in accordance with 5 U.S.C. 552(a) and 1 CFR part 51. Copies may be obtained from Hartzell Propeller, Inc. , Technical Publications Department, One Propeller Place, Piqua, OH 45356; telephone (937) 778-4200, FAX (937) 778-4365. Copies may be inspected at the FAA, New England Region, Office of theRegional Counsel, 12 New England Executive Park, Burlington, MA; or at the Office of the Federal Register, 800 North Capitol Street NW, Suite 700, Washington, DC.

(h) This amendment becomes effective December 20, 1999.

On March 2, 1999, the Federal Aviation Administration (FAA) issued telegraphic airworthiness directive (TAD) T99-06-51, applicable to Hartzell Propeller, Inc., Model HD-E6C-3( ), to require an initial and repetitive inspections of the propeller hub, regardless of propeller hub part number (P/N), for cracks or grease leaks, and replacement of the hub if any cracks are found. That action was prompted by a report of cracks in the propeller hub on a Hartzell Propeller, Inc. model HD-E6C-3B/E13890K propeller installed on a Fairchild Dornier 328-100 series airplane. Shortly after takeoff, the pilot reported severe vibration. The pilot turned back and landed at the departure airport, but an engine was not shut down in flight because the pilot could not determine which engine had a problem. During taxi back to the ramp, the pilot reported that the vibration was worse at ground idle. After shutdown, the propeller was removed and large cracks were discovered in both hub halves. That condition, if not corrected, could result in propeller blade loss due to cracks in the propeller hub that could result in loss of control and possible damage to the airplane. Investigations have found that the cracks were propagating due to fatigue cycles. The nature or origin of the crack initiation flaw could not be determined due to the lack of physical evidence available in the post-failure hardware.

Events Since the Telegraphic AD

Since the issuance of that telegraphic AD, the FAA has determined that only Hartzell propeller hub, P/N D-5108-1, needs to be inspected. Also, the FAA has approved the replacement of Hartzell propeller hub, P/N D-5108-1 with an improved design Hartzell propeller hub, P/N D-5108-5, as terminating action for the inspection requirement. The improved design of the D-5108-5 hub addresses all determined possible causes of crack initiation. Service Information The FAA has reviewed and approved the technical contents of Hartzell Propeller, Inc. Alert Service Bulletin (ASB) HD-ASB-61-021, Revision 1, dated March 18, 1999, that describes procedures for visual inspections of propeller hubs for cracks and grease leaks and for replacing the propeller hub. Required Actions Since an unsafe condition has been identified that is likely to exist or develop on other propellers of the same type design, this AD supersedes telegraphic AD T99-06-51 to require an initial visual inspection of the Hartzell propeller hub, P/N D-5108-1, within 12 hours time-in-service after the effective date of this AD, and repetitive inspections at the start of each operational day and replacement of propeller hub P/N D-5108-1, with propeller hub P/N D-5108-5, within 600 hours TIS or three months after the effective date of this AD. The actions are required to be accomplished in accordance with the alert service bulletin described previously. Immediate Action Since a situation exists that requires the immediate adoption of this regulation, it is found that notice and opportunity for prior public comment hereon are impracticable, and that good cause exists for making this amendment effective in less than 30 days.

Comments Invited

Although this action is in the form of a final rule that involves requirements affecting flight safety and, thus, was not preceded by notice and an opportunity for public comment, comments are invited on this rule. Interested persons are invited to comment on this rule by submitting such written data, views, or arguments as they may desire. Communications should identify the Rules Docket number and be submitted in triplicate to the address specified under the caption "ADDRESSES." All communications received on or before the closing date for comments will be considered, and this rule may be amended in light of the comments received. Factual information that supports the commenter's ideas and suggestions is extremely helpful in evaluating the effectiveness of the AD action and determining whether additional rulemaking action would be needed.

Comments are specifically invited on the overall regulatory, economic, environmental, and energy aspects of the rule that might suggest a need to modify the rule. All comments submitted will be available, both before and after the closing date for comments, in the Rules Docket for examination by interested persons. A report that summarizes each FAA-public contact concerned with the substance of this AD will be filed in the Rules Docket. Commenters wishing the FAA to acknowledge receipt of their comments submitted in response to this notice must submit a self-addressed, stamped postcard on which the following statement is made: "Comments to Docket Number 99-ANE-18-AD." The postcard will be date stamped and returned to the commenter. This proposed rule does not have federalism implications, as defined in Executive Order 13132, because it would not have a substantial direct effect on the States, on the relationship between the national government and the States, or on the distribution of power and responsibilities among the various levels of government. Accordingly, the FAA has not consulted with state authorities prior to publication of this proposed rule. The FAA has determined that this regulation is an emergency regulation that must be issued immediately to correct an unsafe condition in aircraft, and is not a "significant regulatory action" under Executive Order 12866. It has been determined further that this action involves an emergency regulation under DOT Regulatory Policies and Procedures (44 FR 11034, February 26, 1979). If it is determined that this emergency regulation otherwise would be significant under DOT Regulatory Policies and Procedures, a final regulatory evaluation will be prepared and placed in the Rules Docket. A copy of it, if filed, may be obtained from the Rules Docket at the location provided under the caption "ADDRESSES."

List of Subjects in 14 CFR Part 39 Air transportation, Aircraft, Aviation safety, Incorporation by reference, Safety.

Adoption of the Amendment
Accordingly, pursuant to the authority delegated to me by the Administrator, the Federal Aviation Administration amends part 39 of the Federal Aviation Regulations (14 CFR part 39) as follows:

PART 39 - AIRWORTHINESS DIRECTIVES 1. The authority citation for part 39 continues to read as follows: Authority: 49 U.S.C. 106(g), 40113, 44701. 39.13 [Amended] 2. Section 39.13 is amended by adding the following new airworthiness directive: